Alzheimer?s disease (AD) and frontotemporal dementia (FTD) lead to profound cognitive, emotional, and functional deficits. As the disease progresses, the person with dementia (PWD) becomes increasingly dependent on a caregiver (CG) for functional, psychological, and economic assistance. Caring for a PWD is a highly meaningful part of family life but can have adverse consequences for CGs including increased economic hardships, reduced health and well-being, and greater mortality. When CGs suffer these effects, their ability to provide high quality care for PWDs can become comprised, leading to an accelerating cycle of decline. Importantly, beneath these sobering group-level data are striking differences among individual caregivers in how profoundly they experience adverse effects, which raises the possibility that adverse effects of caregiving could be predicted, modified, or even prevented. The proposed research focuses on CG risk associated with emotional functioning in PWDs, CGs, and PWD-CG relationships. This focus reflects the profound impact that problematic emotional behaviors and psychological symptoms in PWDs have on CGs, the strong links between emotions and health, and our previous research linking emotional factors with adverse CG outcomes. CGs and PWDs will undergo a comprehensive, laboratory-based assessment of: (a) emotional reactivity?ability to generate emotional responses to significant challenges and opportunities; (b) emotion regulation?ability to adjust emotional responses to meet situational demands; and (c) emotion recognition?ability to detect emotions accurately in others and respond appropriately. Five studies are proposed to address four specific aims: Aim 1: To determine how emotional functioning in PWDs, CGs, and PWD-CG relationships is associated with individual differences in adverse CG outcomes (i.e., lower CG mental health, physical health, and well- being) during active caregiving (Study 1, N=180) and after caregiving has ended (Study 2, N=200). Aim 2: To use longitudinal assessments to evaluate hypothesized biological and behavioral pathways connecting risk factors with adverse CG outcomes during active caregiving (Study 3, N=84 studied for 3 years). Aim 3: To examine relationships between changes in CG health and PWD mortality (Study 4, N=400). Aim 4: To identify an optimal set of laboratory-based measures of emotional functioning for predicting adverse CG outcomes both during and after active caregiving and to determine their incremental validity compared to other established risk factors and traditional survey measures of emotional functioning (Study 5, N=350). Innovations include: (a) multidisciplinary approach (psychology, neurology, and nursing); (b) translational application of laboratory-based methods used in basic affective science methodology to CG research; (c) including CGs of individuals with both AD and FTD; (d) focusing on interpersonal functioning; (e) examining individual differences in adverse CG outcomes both during and after active caregiving; (f) examining adverse outcomes for both CGs and PWDs; and (g) longitudinal behavioral and biological assessments of CG functioning.